1
|
Aqdam MM, Baltzer JL, Branfireun BA, Low G, Low M, Swanson HK. Can remotely sensed catchment to lake area ratios predict mercury levels in subarctic fishes? ENVIRONMENTAL RESEARCH 2024; 260:119545. [PMID: 38986798 DOI: 10.1016/j.envres.2024.119545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2024] [Revised: 06/28/2024] [Accepted: 07/01/2024] [Indexed: 07/12/2024]
Abstract
Mercury concentrations ([Hg]) in fish reflect a complex array of interacting biogeochemical and ecological variables. In northern regions where fish are a critical subsistence food, understanding and predicting fish [Hg] can be particularly difficult, largely due to a paucity of comprehensive data associated with the logistical challenges of field sampling. Building on previous work where we elucidated causal relationships between fish [Hg] and a variety of catchment, water quality, and ecological variables in subarctic lakes, we investigated whether using only ratios of catchment area to lake area (CA:LA) can predict [Hg] in northern freshwater fish species. As CA:LA can be sensed remotely, they may be more feasible and practical to obtain than field data in far northern regions. Our study included thirteen remote lakes that represent a CA:LA gradient of 6.2-423.5 within an ∼66,000 km2 subarctic region of Northwest Territories, Canada. We found that size-standardized [Hg] in three widespread fish species, including Lake Whitefish (Coregonus clupeaformis), Walleye (Sander vitreus), and Northern Pike (Esox lucius), were significantly and positively related to CA:LA (p < 0.007, r2 = 67-80%), indicating higher fish [Hg] in smaller lakes surrounded by relatively larger catchments. Our findings provide compelling evidence that remotely sensed CA:LA can be used to predict [Hg] in northern fishes and aid in prioritizing understudied and subsistence fishing lakes of the Canadian subarctic for [Hg] monitoring programs.
Collapse
Affiliation(s)
- Mehdi M Aqdam
- Department of Biology, Wilfrid Laurier University, Waterloo, ON, Canada; Azimuth Consulting Group Inc., Vancouver, BC, Canada.
| | | | | | - George Low
- Dehcho Aboriginal Aquatic Resources & Oceans Management, Hay River, NT, Canada
| | - Mike Low
- Dehcho Aboriginal Aquatic Resources & Oceans Management, Hay River, NT, Canada
| | - Heidi K Swanson
- Department of Biology, Wilfrid Laurier University, Waterloo, ON, Canada.
| |
Collapse
|
2
|
Janiga M, Janiga M, Pitoňáková T. Differential accumulation of metals in the lacustrine and fluvial Alpine bullheads (Cottus poecilopus) and recovery of fish from metal contamination after a flash flood. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024; 31:17387-17400. [PMID: 38340297 PMCID: PMC10894169 DOI: 10.1007/s11356-024-32288-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Accepted: 01/27/2024] [Indexed: 02/12/2024]
Abstract
The spatiotemporal distribution and transport of mercury, zinc, molybdenum, rubidium, and strontium from alpine terrestrial ecosystems to alpine lake and mountain stream populations of Cottus poecilopus were investigated. Metals were measured for 66 wild fish collected from different lakes and Javorinka stream across. Mercury was measured in the pectoral fins, other elements in the skull. Bullheads contained more metals in the alpine lakes than in the mountain stream. In particular, mercury and zinc concentrations in lake bullheads were 6 and 2.5 times higher, respectively, than those of stream-dwelling fish. New data were generated on metal bioaccumulation in fish of understudied West Carpathian alpine lake environments. In July 2018, a major flood occurred in the area of the Javorinka. Already then, the mercury content in bullheads increased significantly. Bioaccumulation of mercury in fish occurred very quickly after the flood and was also significant in the following 2019. Then, the concentrations of mercury quickly decreased up to 70% in 2021-2022. Average concentrations of molybdenum and rubidium in bullheads in the stream rapidly declined in the year following the flood disturbance, but within less than 2 years, the metal levels stabilized at about the same level as in 2017 prior the flood. Strontium concentrations in fish dropped rapidly immediately after the flood, increased in the following years, and dropped again after 4 years, suggesting that many more factors are influencing strontium bioaccumulation in fish that are comparable in magnitude to the flood. The most serious warning seems to be the absence of biogenic zinc. The average concentration in the Alpine bullheads population in the stream has declined by 70% in less than 5 years and is steadily declining. An important result of this study is the demonstration that disturbance by a single factor (heavy rainfall and flooding) has a clear and timely effect on average metal concentrations in the fish population.
Collapse
Affiliation(s)
- Marián Janiga
- Institute of High Mountain Biology, University of Žilina, Tatranská Javorina 7, 059 56, Žilina, Tatranská Javorina, Slovakia
| | - Martin Janiga
- Institute of High Mountain Biology, University of Žilina, Tatranská Javorina 7, 059 56, Žilina, Tatranská Javorina, Slovakia
- Faculty of Humanities and Natural Scienes, University of Presov, Presov, Slovakia
| | - Tatiana Pitoňáková
- Institute of High Mountain Biology, University of Žilina, Tatranská Javorina 7, 059 56, Žilina, Tatranská Javorina, Slovakia.
| |
Collapse
|
3
|
Herring G, Tennant LB, Willacker JJ, Johnson M, Siegel RB, Polasik JS, Eagles-Smith CA. Wildfire burn severity and stream chemistry influence aquatic invertebrate and riparian avian mercury exposure in forested ecosystems. ECOTOXICOLOGY (LONDON, ENGLAND) 2024; 33:131-141. [PMID: 38381206 DOI: 10.1007/s10646-024-02730-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 01/08/2024] [Indexed: 02/22/2024]
Abstract
Terrestrial soils in forested landscapes represent some of the largest mercury (Hg) reserves globally. Wildfire can alter the storage and distribution of terrestrial-bound Hg via reemission to the atmosphere or mobilization in watersheds where it may become available for methylation and uptake into food webs. Using data associated with the 2007 Moonlight and Antelope Fires in California, we examined the long-term direct effects of wildfire burn severity on the distribution and magnitude of Hg concentrations in riparian food webs. Additionally, we quantified the cross-ecosystem transfer of Hg from aquatic invertebrate to riparian bird communities; and assessed the influence of biogeochemical, landscape variables, and ecological factors on Hg concentrations in aquatic and terrestrial food webs. Benthic macroinvertebrate methylmercury (MeHg) and riparian bird blood total mercury (THg) concentrations varied by 710- and 760-fold, respectively, and Hg concentrations were highest in predators. We found inconsistent relationships between Hg concentrations across and within taxa and guilds in response to stream chemical parameters and burn severity. Macroinvertebrate scraper MeHg concentrations were influenced by dissolved organic carbon (DOC); however, that relationship was moderated by burn severity (as burn severity increased the effect of DOC declined). Omnivorous bird Hg concentrations declined with increasing burn severity. Overall, taxa more linked to in situ energetic pathways may be more responsive to the biogeochemical processes that influence MeHg cycling. Remarkably, 8 years post-fire, we still observed evidence of burn severity influencing Hg concentrations within riparian food webs, illustrating its overarching role in altering the storage and redistribution of Hg and influencing biogeochemical processes.
Collapse
Affiliation(s)
- Garth Herring
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, Corvallis, OR, 97331, USA.
| | - Lora B Tennant
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, Corvallis, OR, 97331, USA
- Nez Perce Tribe, Department of Fisheries Resource Management, Joseph, OR, 97846, USA
| | - James J Willacker
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, Corvallis, OR, 97331, USA
| | - Matthew Johnson
- National Park Service, Inventory & Monitoring Division, Southern Colorado Plateau Network, Flagstaff, AZ, 86001, USA
| | - Rodney B Siegel
- The Institute for Bird Populations, Petaluma, CA, 94953, USA
| | - Julia S Polasik
- The Institute for Bird Populations, Petaluma, CA, 94953, USA
- Teton Raptor Center, Wilson, WY, 83014, USA
| | - Collin A Eagles-Smith
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, Corvallis, OR, 97331, USA
| |
Collapse
|
4
|
Nelson SJ, Willacker J, Eagles-Smith C, Flanagan Pritz C, Chen CY, Klemmer A, Krabbenhoft DP. Habitat and dissolved organic carbon modulate variation in the biogeochemical drivers of mercury bioaccumulation in dragonfly larvae at the national scale. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 912:169396. [PMID: 38114036 DOI: 10.1016/j.scitotenv.2023.169396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 12/11/2023] [Accepted: 12/12/2023] [Indexed: 12/21/2023]
Abstract
We paired mercury (Hg) concentrations in dragonfly larvae with water chemistry in 29 U.S. national parks to highlight how ecological and biogeochemical context (habitat, dissolved organic carbon [DOC]) influence drivers of Hg bioaccumulation. Although prior studies have defined influences of biogeochemical variables on Hg production and bioaccumulation, it has been challenging to determine their influence across diverse habitats, regions, or biogeochemical conditions within a single study. We compared global (i.e., all sites), habitat-specific, and DOC-class models to illuminate how these controls on biotic Hg vary. Although the suite of important biogeochemical factors across all sites (e.g., aqueous Hg, DOC, sulfate [SO42-], and pH) was consistent with general findings in the literature, contrasting the restricted models revealed more nuanced controls on biosentinel Hg. Comparing habitats, aqueous (filtered) total mercury (THg) and SO42- were important in lentic systems whereas aqueous (filtered) methylmercury (MeHg), DOC, pH, and SO42- were important in lotic and wetland systems. The ability to identify important variables varied among habitats, with less certainty in lentic (model weight (W) = 0.05) than lotic (W = 0.11) or wetland habitats (W = 0.23), suggesting that biogeochemical drivers of bioaccumulation are more variable, or obscured by other aspects of Hg cycling, in these habitats. Results revealed a contrast in the importance of aqueous MeHg versus aqueous THg between DOC-classes: in low-DOC sites (<8.5 mg/L), availability of upstream inputs of MeHg appeared more important for bioaccumulation; in high-DOC sites (>8.5 mg/L) THg was more important, suggesting a link to in-situ controls on bioavailability of Hg for MeHg production. Mercury bioaccumulation (indicated by bioaccumulation factor) was more efficient in low DOC-class sites, likely due to reduced partitioning of aqueous MeHg to DOC. Together, findings highlight substantial variation in the drivers of Hg bioaccumulation and suggest consideration of these factors in natural resource management and decision-making.
Collapse
Affiliation(s)
- Sarah J Nelson
- Appalachian Mountain Club, Gorham, NH 03581, USA; University of Maine, School of Forest Resources, Orono, ME 04469, USA.
| | - James Willacker
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, 3200 SW Jefferson Way, Corvallis, OR 97330, USA
| | - Collin Eagles-Smith
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, 3200 SW Jefferson Way, Corvallis, OR 97330, USA
| | - Colleen Flanagan Pritz
- National Park Service, Air Resources Division, Natural Resource, Stewardship and Science Directorate, Lakewood, CO 80228, USA
| | | | - Amanda Klemmer
- School of Biology and Ecology, University of Maine, 5722 Deering Hall, Orono, ME 04469, USA
| | - David P Krabbenhoft
- U.S. Geological Survey, Upper Midwest Water Science Center, 1 Gifford Pinchot Dr., Madison, WI 53726, USA
| |
Collapse
|
5
|
Bartz KK, Hannam MP, Wilson TL, Lepak RF, Ogorek JM, Young DB, Eagles-Smith CA, Krabbenhoft DP. Understanding drivers of mercury in lake trout (Salvelinus namaycush), a top-predator fish in southwest Alaska's parklands. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 330:121678. [PMID: 37119998 PMCID: PMC10716799 DOI: 10.1016/j.envpol.2023.121678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 04/10/2023] [Accepted: 04/19/2023] [Indexed: 05/13/2023]
Abstract
Mercury (Hg) is a widespread element and persistent pollutant, harmful to fish, wildlife, and humans in its organic, methylated form. The risk of Hg contamination is driven by factors that regulate Hg loading, methylation, bioaccumulation, and biomagnification. In remote locations, with infrequent access and limited data, understanding the relative importance of these factors can pose a challenge. Here, we assessed Hg concentrations in an apex predator fish species, lake trout (Salvelinus namaycush), collected from 14 lakes spanning two National Parks in southwest Alaska, U.S.A. We then examined factors associated with the variation in fish Hg concentrations using a Bayesian hierarchical model. We found that total Hg concentrations in water were consistently low among lakes (0.11-0.50 ng L-1). Conversely, total Hg concentrations in lake trout spanned a thirty-fold range (101-3046 ng g-1 dry weight), with median values at 7 lakes exceeding Alaska's human consumption threshold. Model results showed that fish age and, to a lesser extent, body condition best explained variation in Hg concentration among fish within a lake, with Hg elevated in older, thinner lake trout. Other factors, including plankton methyl Hg content, fish species richness, volcano proximity, and glacier loss, best explained variation in lake trout Hg concentration among lakes. Collectively, these results provide evidence that multiple, hierarchically nested factors control fish Hg levels in these lakes.
Collapse
Affiliation(s)
- Krista K Bartz
- National Park Service, Southwest Alaska Inventory and Monitoring Network, 240 West 5th Avenue, Anchorage, AK, 99501, USA.
| | - Michael P Hannam
- National Park Service, Southwest Alaska Inventory and Monitoring Network, 240 West 5th Avenue, Anchorage, AK, 99501, USA
| | - Tammy L Wilson
- National Park Service, Southwest Alaska Inventory and Monitoring Network, 240 West 5th Avenue, Anchorage, AK, 99501, USA
| | - Ryan F Lepak
- Environmental Chemistry and Technology Program, University of Wisconsin-Madison, Madison, WI, 53706, USA; U.S. Environmental Protection Agency Office of Research and Development, Center for Computational Toxicology and Exposure, Great Lakes Toxicology and Ecology Division, 6201 Congdon Blvd, Duluth, MN, 55804, USA
| | - Jacob M Ogorek
- U.S. Geological Survey, Upper Midwest Water Science Center, Mercury Research Laboratory, 1 Gifford Pinchot Dr, Madison, WI, 53726, USA
| | - Daniel B Young
- National Park Service, Lake Clark National Park and Preserve, 240 West 5th Avenue, Anchorage, AK, 99501, USA
| | - Collin A Eagles-Smith
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, Corvallis, OR, 97330, USA
| | - David P Krabbenhoft
- U.S. Geological Survey, Upper Midwest Water Science Center, Mercury Research Laboratory, 1 Gifford Pinchot Dr, Madison, WI, 53726, USA
| |
Collapse
|
6
|
Rowland FE, Muths E, Eagles-Smith CA, Stricker CA, Kraus JM, Harrington RA, Walters DM. Complex Life Histories Alter Patterns of Mercury Exposure and Accumulation in a Pond-Breeding Amphibian. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:4133-4142. [PMID: 36848500 DOI: 10.1021/acs.est.2c04896] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Quantifying how contaminants change across life cycles of species that undergo metamorphosis is critical to assessing organismal risk, particularly for consumers. Pond-breeding amphibians can dominate aquatic animal biomass as larvae and are terrestrial prey as juveniles and adults. Thus, amphibians can be vectors of mercury exposure in both aquatic and terrestrial food webs. However, it is still unclear how mercury concentrations are affected by exogenous (e.g., habitat or diet) vs endogenous factors (e.g., catabolism during hibernation) as amphibians undergo large diet shifts and periods of fasting during ontogeny. We measured total mercury (THg), methylmercury (MeHg), and isotopic compositions (δ 13C, δ15N) in boreal chorus frogs (Pseudacris maculata) across five life stages in two Colorado (USA) metapopulations. We found large differences in concentrations and percent MeHg (of THg) among life stages. Frog MeHg concentrations peaked during metamorphosis and hibernation coinciding with the most energetically demanding life cycle stages. Indeed, life history transitions involving periods of fasting coupled with high metabolic demands led to large increases in mercury concentrations. The endogenous processes of metamorphosis and hibernation resulted in MeHg bioamplification, thus decoupling it from the light isotopic proxies of diet and trophic position. These step changes are not often considered in conventional expectations of how MeHg concentrations within organisms are assessed.
Collapse
Affiliation(s)
- Freya E Rowland
- Columbia Environmental Research Center, U.S. Geological Survey, Columbia, Missouri 65201, United States
| | - Erin Muths
- Fort Collins Science Center, U.S. Geological Survey, Fort Collins, Colorado 80526, United States
| | - Collin A Eagles-Smith
- Forest and Rangeland Ecosystem Science Center, U.S. Geological Survey, Corvallis, Oregon 97331, United States
| | - Craig A Stricker
- Fort Collins Science Center, U.S. Geological Survey, Fort Collins, Colorado 80526, United States
| | - Johanna M Kraus
- Columbia Environmental Research Center, U.S. Geological Survey, Columbia, Missouri 65201, United States
| | - Rachel A Harrington
- U.S. Environmental Protection Agency, Region 8, Denver, Colorado 80202, United States
| | - David M Walters
- Columbia Environmental Research Center, U.S. Geological Survey, Columbia, Missouri 65201, United States
| |
Collapse
|
7
|
Eckley CS, Eagles-Smith C, Luxton TP, Hoffman J, Janssen S. Using mercury stable isotope fractionation to identify the contribution of historical mercury mining sources present in downstream water, sediment and fish. FRONTIERS IN ENVIRONMENTAL CHEMISTRY 2023; 4:1096199. [PMID: 37323923 PMCID: PMC10269370 DOI: 10.3389/fenvc.2023.1096199] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Ecosystems downstream of mercury (Hg) contaminated sites can be impacted by both localized releases as well as Hg deposited to the watershed from atmospheric transport. Identifying the source of Hg in water, sediment, and fish downstream of contaminated sites is important for determining the effectiveness of source-control remediation actions. This study uses measurements of Hg stable isotopes in soil, sediment, water, and fish to differentiate between Hg from an abandoned Hg mine from non-mine-related sources. The study site is located within the Willamette River watershed (Oregon, United States), which includes free-flowing river segments and a reservoir downstream of the mine. The concentrations of total-Hg (THg) in the reservoir fish were 4-fold higher than those further downstream (>90 km) from the mine site in free-flowing sections of the river. Mercury stable isotope fractionation analysis showed that the mine tailings (δ202Hg: -0.36‰ ± 0.03‰) had a distinctive isotopic composition compared to background soils (δ202Hg: -2.30‰ ± 0.25‰). Similar differences in isotopic composition were observed between stream water that flowed through the tailings (particulate bound δ202Hg: -0.58‰; dissolved: -0.91‰) versus a background stream (particle-bound δ202Hg: -2.36‰; dissolved: -2.09‰). Within the reservoir sediment, the Hg isotopic composition indicated that the proportion of the Hg related to mine-release increased with THg concentrations. However, in the fish samples the opposite trend was observed-the degree of mine-related Hg was lower in fish with the higher THg concentrations. While sediment concentrations clearly show the influence of the mine, the relationship in fish is more complicated due to differences in methylmercury (MeHg) formation and the foraging behavior of different fish species. The fish tissue δ13C and Δ199Hg values indicate that there is a higher influence of mine-sourced Hg in fish feeding in a more sediment-based food web and less so in planktonic and littoral-based food webs. Identifying the relative proportion of Hg from local contaminated site can help inform remediation decisions, especially when the relationship between total Hg concentrations and sources do not show similar covariation between abiotic and biotic media.
Collapse
Affiliation(s)
| | - Collin Eagles-Smith
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, Corvallis, OR, United States
| | - Todd P. Luxton
- US EPA ORD, Center for Environmental Solutions and Emergency Response, Cincinnati, OH, United States
| | - Joel Hoffman
- U.S. EPA Office of Research and Development, Center for Computational Toxicology and Exposure, Great Lakes Toxicology and Ecology Division, Duluth, MN, United States
| | - Sarah Janssen
- U.S. Geological Survey, Mercury Research Lab, Upper Midwest Water Science Center, Madison, WI, United States
| |
Collapse
|
8
|
Drenner RW, Chumchal MM, Adams KJ, Seymour RD. Effect of Land Cover on Ecoregion-Scale Spatial Patterns of Mercury Contamination of Largemouth Bass in the Southeastern United States. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2022; 41:2386-2394. [PMID: 35975571 DOI: 10.1002/etc.5426] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 11/03/2021] [Accepted: 06/30/2022] [Indexed: 06/15/2023]
Abstract
Consumption of methylmercury (MeHg)-contaminated fish is the primary source of MeHg in humans and poses a hazard to human health. Because of widespread atmospheric deposition of inorganic mercury (IHg), all water bodies in the United States have been contaminated with Hg. In aquatic ecosystems, IHg is converted to MeHg, which biomagnifies, reaching high concentrations in piscivorous fish. It is not possible for governmental agencies to monitor fish from every waterbody to determine if concentrations of MeHg in fish are hazardous to human health. To help government agencies focus their monitoring efforts, it is critical that we develop the ability to predict regions where waterbodies are most likely to contain fish with hazardous concentrations of MeHg. The objective of the present study was to examine the relationship between MeHg contamination of largemouth bass (Micropterus salmoides), a popular piscivorous gamefish, and land cover in 24 ecoregions across 15 states in the southeastern United States. In our study we demonstrate for the first time that 72% of the variance in average concentrations of MeHg in largemouth bass between ecoregions of the southeastern United States can be explained by the percentage coverage by evergreen forests, emergent herbaceous wetlands, and pasture/hay. Land cover determines the sensitivity of freshwater systems to atmospheric IHg deposition, and the present study suggests that at the ecoregion scale, MeHg bioaccumulation in piscivorous gamefish, and ultimately the health hazard that these MeHg-contaminated fish pose to humans, can be in part predicted by land-cover type. Environ Toxicol Chem 2022;41:2386-2394. © 2022 SETAC.
Collapse
Affiliation(s)
- Ray W Drenner
- Biology Department, Texas Christian University, Fort Worth, Texas, USA
| | | | - Kimberly J Adams
- Biology Department, Texas Christian University, Fort Worth, Texas, USA
| | - Ryan D Seymour
- Biology Department, Texas Christian University, Fort Worth, Texas, USA
| |
Collapse
|
9
|
Moslemi-Aqdam M, Baker LF, Baltzer JL, Branfireun BA, Evans MS, Laird BD, Low G, Low M, Swanson HK. Understanding among-lake variability of mercury concentrations in Northern Pike (Esox lucius): A whole-ecosystem study in subarctic lakes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 822:153430. [PMID: 35090925 DOI: 10.1016/j.scitotenv.2022.153430] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 01/04/2022] [Accepted: 01/22/2022] [Indexed: 06/14/2023]
Abstract
Mercury concentrations ([Hg]) in fish reflect complex biogeochemical and ecological interactions that occur at a range of spatial and biological scales. Elucidating these interactions is crucial to understanding and predicting fish [Hg], particularly at northern latitudes, where environmental perturbations are having profound effects on land-water-animal interactions, and where fish are a critical subsistence food source. Using data from eleven subarctic lakes that span an area of ~60,000 km2 in the Dehcho Region of Northwest Territories (Canada), we investigated how trophic ecology and growth rates of fish, lake water chemistry, and catchment characteristics interact to affect [Hg] in Northern Pike (Esox lucius), a predatory fish of widespread subsistence and commercial importance. Results from linear regression and piecewise structural equation models showed that 83% of among-lake variability in Northern Pike [Hg] was explained by fish growth rates (negative) and concentrations of methyl Hg ([MeHg]) in benthic invertebrates (positive). These variables were in turn influenced by concentrations of dissolved organic carbon, MeHg (water), and total Hg (sediment) in lakes, which were ultimately driven by catchment characteristics. Lakes in relatively larger catchments and with more temperate/subpolar needleleaf and mixed forests had higher [Hg] in Northern Pike. Our results provide a plausible mechanistic understanding of how interacting processes at scales ranging from whole catchments to individual organisms influence fish [Hg], and give insight into factors that could be considered for prioritizing lakes for monitoring in subarctic regions.
Collapse
Affiliation(s)
| | - Leanne F Baker
- Department of Biology, University of Waterloo, Waterloo, ON, Canada
| | | | | | - Marlene S Evans
- Water Science and Technology Directorate, Environment and Climate Change Canada, Saskatoon, SK, Canada
| | - Brian D Laird
- School of Public Health Sciences, University of Waterloo, Waterloo, ON, Canada
| | - George Low
- Dehcho Aboriginal Aquatic Resources & Oceans Management, Hay River, NT, Canada
| | - Mike Low
- Dehcho Aboriginal Aquatic Resources & Oceans Management, Hay River, NT, Canada
| | - Heidi K Swanson
- Department of Biology, University of Waterloo, Waterloo, ON, Canada; Water Institute, University of Waterloo, Waterloo, ON, Canada
| |
Collapse
|
10
|
Chumchal MM, Beaubien GB, Drenner RW, Hannappel MP, Mills MA, Olson CI, Otter RR, Todd AC, Walters DM. Use of Riparian Spiders as Sentinels of Persistent and Bioavailable Chemical Contaminants in Aquatic Ecosystems: A Review. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2022; 41:499-514. [PMID: 35113469 PMCID: PMC9703374 DOI: 10.1002/etc.5267] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Revised: 11/30/2021] [Accepted: 12/05/2021] [Indexed: 05/29/2023]
Abstract
Aquatic ecosystems around the world are contaminated with a wide range of anthropogenic chemicals, including metals and organic pollutants, that originate from point and nonpoint sources. Many of these chemical contaminants have complex environmental cycles, are persistent and bioavailable, can be incorporated into aquatic food webs, and pose a threat to the health of wildlife and humans. Identifying appropriate sentinels that reflect bioavailability is critical to assessing and managing aquatic ecosystems impacted by contaminants. The objective of the present study is to review research on riparian spiders as sentinels of persistent and bioavailable chemical contaminants in aquatic ecosystems. Our review of the literature on riparian spiders as sentinels suggests that significant progress has been made during the last two decades of research. We identified 55 published studies conducted around the world in which riparian spiders (primarily of the families Tetragnathidae, Araneidae, Lycosidae, and Pisauridae) were used as sentinels of chemical contamination of lotic, lentic, and estuarine systems. For several contaminants, such as polychlorinated biphenyls (PCBs), Hg, and Se, it is now clear that riparian spiders are appropriate sentinels. However, many contaminants and factors that could impact chemical concentrations in riparian spiders have not been well characterized. Further study of riparian spiders and their potential role as sentinels is critical because it would allow for development of national-scale programs that utilize riparian spiders as sentinels to monitor chemical contaminants in aquatic ecosystems. A riparian spider sentinel program in the United States would be complementary to existing national sentinel programs, including those for fish and immature dragonflies. Environ Toxicol Chem 2022;41:499-514. © 2021 SETAC.
Collapse
Affiliation(s)
| | - Gale B. Beaubien
- Office of Research and Development, Center for Environmental Solutions and Emergency Response, US Environmental Protection Agency, Cincinnati, Ohio
| | - Ray W. Drenner
- Biology Department, Texas Christian University, Fort Worth, Texas, USA
| | | | - Marc A. Mills
- Office of Research and Development, Center for Environmental Solutions and Emergency Response, US Environmental Protection Agency, Cincinnati, Ohio
| | - Connor I. Olson
- Department of Civil and Environmental Engineering, Syracuse University, Syracuse, New York, USA
| | - Ryan R. Otter
- Department of Biology, Molecular Bioscience, Data Science Institute, Middle Tennessee State University, Murfreesboro, Tennessee, USA
| | - Andrew C. Todd
- Biology Department, Texas Christian University, Fort Worth, Texas, USA
| | - David M. Walters
- US Geological Survey, Columbia Environmental Research Center, Columbia, Missouri
| |
Collapse
|
11
|
Liu HW, Yu B, Yang L, Wang LL, Fu JJ, Liang Y, Bu D, Yin YG, Hu LG, Shi JB, Jiang GB. Terrestrial mercury transformation in the Tibetan Plateau: New evidence from stable isotopes in upland buzzards. JOURNAL OF HAZARDOUS MATERIALS 2020; 400:123211. [PMID: 32593022 DOI: 10.1016/j.jhazmat.2020.123211] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 06/05/2020] [Accepted: 06/14/2020] [Indexed: 06/11/2023]
Abstract
Understanding the geochemical cycle of mercury (Hg) in the high-altitude Tibetan Plateau is of great value for studying the long-range transport of Hg. Herein, speciation and isotopic compositions of Hg in the muscle and feathers of upland buzzards (Buteo hemilasius) were studied to trace the terrestrial transformation of Hg in the Tibetan Plateau. Very low Hg content and relatively low δ202Hg values (feather: -0.77 ± 0.50‰, n = 9, muscle: -1.29 ± 0.29‰, n = 13, 1SD) were observed in upland buzzards. In contrast, the Δ199Hg values could be as high as 2.89‰ in collected samples. To our knowledge, this is the highest Δ199Hg value reported in avian tissues. Moreover, upland buzzards showed significantly different Δ199Hg values from fish collected from the same region, suggesting different generation and transformation processes of methylmercury (MeHg) in terrestrial and aquatic ecosystems. We speculated that different percentages of Hg undergoing photochemical reactions and contributions of atmospheric MeHg were possible reasons for observed differences. The results provide new clues for different circulation histories of Hg in terrestrial and aquatic ecosystems, which will be critical for further study of geochemical cycle and ecological risk of Hg in the environment.
Collapse
Affiliation(s)
- Hong-Wei Liu
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China; State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Ben Yu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Lin Yang
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China; State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Lin-Lin Wang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; Institute of Environment and Health, Jianghan University, Wuhan 430056, China
| | - Jian-Jie Fu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; School of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, 310000, China
| | - Yong Liang
- Institute of Environment and Health, Jianghan University, Wuhan 430056, China
| | - Duo Bu
- Science Faculty, Tibet University, Lhasa 850000, China
| | - Yong-Guang Yin
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Li-Gang Hu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Jian-Bo Shi
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China; State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; School of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, 310000, China.
| | - Gui-Bin Jiang
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China; State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| |
Collapse
|
12
|
Nelson SJ, Chen CY, Kahl JS. Dragonfly larvae as biosentinels of Hg bioaccumulation in Northeastern and Adirondack lakes: relationships to abiotic factors. ECOTOXICOLOGY (LONDON, ENGLAND) 2020; 29:1659-1672. [PMID: 31883061 PMCID: PMC8418898 DOI: 10.1007/s10646-019-02149-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 12/05/2019] [Indexed: 05/28/2023]
Abstract
Mercury (Hg) is a toxic pollutant, widespread in northeastern US ecosystems. Resource managers' efforts to develop fish consumption advisories for humans and to focus conservation efforts for fish-eating wildlife are hampered by spatial variability. Dragonfly larvae can serve as biosentinels for Hg given that they are widespread in freshwaters, long-lived, exhibit site fidelity, and bioaccumulate relatively high mercury concentrations, mostly as methylmercury (88% ± 11% MeHg in this study). We sampled lake water and dragonfly larvae in 74 northeastern US lakes that are part of the US EPA Long-Term Monitoring Network, including 45 lakes in New York, 43 of which are in the Adirondacks. Aqueous dissolved organic carbon (DOC) and total Hg (THg) were strongly related to MeHg in lake water. Dragonfly larvae total mercury ranged from 0.016-0.918 μg/g, dw across the study area; Adirondack lakes had the minimum and maximum concentrations. Aqueous MeHg and dragonfly THg were similar between the Adirondack and Northeast regions, but a majority of lakes within the highest quartile of dragonfly THg were in the Adirondacks. Using landscape, lake chemistry, and lake morphometry data, we evaluated relationships with MeHg in lake water and THg in dragonfly larvae. Lakewater DOC and lake volume were strong predictors for MeHg in water. Dragonfly THg Bioaccumulation Factors (BAFs, calculated as [dragonfly THg]:[aqueous MeHg]) increased as lake volume increased, suggesting that lake size influences Hg bioaccumulation or biomagnification. BAFs declined with increasing DOC, supporting a potential limiting effect for MeHg bioavailability with higher DOC.
Collapse
Affiliation(s)
- Sarah J Nelson
- School of Forest Resources, University of Maine, 5755 Nutting Hall, Orono, ME, 04469-5755, USA.
- Appalachian Mountain Club, PO Box 298, Route 16, Gorham, NH, 03581, USA.
| | - Celia Y Chen
- Department of Biological Sciences, Dartmouth College, HB 6044, Class of '78 Life Sciences Center, Hanover, NH, 03755, USA
| | - Jeffrey S Kahl
- Thomas College, School of Arts and Sciences, 180 West River Road, Waterville, ME, 04901, USA
| |
Collapse
|
13
|
Thomas SM, Melles SJ, Mackereth RW, Tunney TD, Chu C, Oswald CJ, Bhavsar SP, Johnston TA. Climate and landscape conditions indirectly affect fish mercury levels by altering lake water chemistry and fish size. ENVIRONMENTAL RESEARCH 2020; 188:109750. [PMID: 32526497 DOI: 10.1016/j.envres.2020.109750] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 05/15/2020] [Accepted: 05/27/2020] [Indexed: 06/11/2023]
Abstract
Mercury pollution is a global environmental problem that threatens ecosystems, and negatively impacts human health and well-being. Mercury accumulation in fish within freshwater lakes is a complex process that appears to be driven by factors such as individual fish biology and water chemistry at the lake-scale, whereas, climate, and land-use/land-cover conditions within lake catchments can be influential at relatively larger scales. Nevertheless, unravelling the intricate network of pathways that govern how lake-scale and large-scale factors interact to affect mercury levels in fish remains an important scientific challenge. Using structural equation models (SEMs) and multiple long-term databases we identified direct and indirect effects of lake-scale and larger-scale factors on mercury levels in Walleye and Northern Pike - two species that are valued in inland fisheries. At the lake-level, the most parsimonious path models contained direct effects of fish weight, DOC, and pH, as well as an indirect effect of DOC on fish mercury levels via fish weight. Interestingly, lakeshed-, climate-, and full-path models that combine the effects of both lakeshed and climate revealed indirect effects of surrounding landscape conditions and latitude via DOC, pH, and fish weight but no direct effects on fish mercury levels. These results are generally consistent across species and lakes, except for some differences between stratified and non-stratified lakes. Our findings imply that understanding climate and land-use driven alterations of water chemistry and fish biology will be critical to predicting and mitigating fish mercury bioaccumulation in the future.
Collapse
Affiliation(s)
- Shyam M Thomas
- Department of Chemistry & Biology, Ryerson University, Toronto, ON M5B 2K3, Canada.
| | - Stephanie J Melles
- Department of Chemistry & Biology, Ryerson University, Toronto, ON M5B 2K3, Canada
| | - Robert W Mackereth
- Ontario Ministry of Natural Resources & Forestry, Centre for Northern Forest Ecosystem Research, Thunder Bay, ON P7E 2V6, Canada
| | - Tyler D Tunney
- Fisheries and Oceans Canada, Freshwater Habitat Section, Gulf Fisheries Centre, Moncton, NB E1C 9B6, Canada
| | - Cindy Chu
- Ontario Ministry of Natural Resources & Forestry, Aquatic Research and Monitoring Section, Peterborough, ON K9L 0G2, Canada
| | - Claire J Oswald
- Department of Geography and Environmental Studies, Ryerson University, Toronto, ON M5B 2K3, Canada
| | - Satyendra P Bhavsar
- Environmental Monitoring and Reporting Branch, Ontario Ministry of the Environment, Conservation and Parks, Toronto, ON M9P 3V6, Canada
| | - Thomas A Johnston
- Ontario Ministry of Natural Resources and Forestry, Cooperative Freshwater Ecology Unit, Vale Living with Lakes Centre, Laurentian University, Sudbury, ON P3E 2C6, Canada
| |
Collapse
|
14
|
Eagles-Smith CA, Willacker JJ, Nelson SJ, Flanagan Pritz CM, Krabbenhoft DP, Chen CY, Ackerman JT, Grant EHC, Pilliod DS. A National-Scale Assessment of Mercury Bioaccumulation in United States National Parks Using Dragonfly Larvae As Biosentinels through a Citizen-Science Framework. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:8779-8790. [PMID: 32633494 PMCID: PMC7790342 DOI: 10.1021/acs.est.0c01255] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 06/03/2020] [Accepted: 06/04/2020] [Indexed: 06/01/2023]
Abstract
We conducted a national-scale assessment of mercury (Hg) bioaccumulation in aquatic ecosystems, using dragonfly larvae as biosentinels, by developing a citizen-science network to facilitate biological sampling. Implementing a carefully designed sampling methodology for citizen scientists, we developed an effective framework for a landscape-level inquiry that might otherwise be resource limited. We assessed the variation in dragonfly Hg concentrations across >450 sites spanning 100 United States National Park Service units and examined intrinsic and extrinsic factors associated with the variation in Hg concentrations. Mercury concentrations ranged between 10.4 and 1411 ng/g dry weight across sites and varied among habitat types. Dragonfly total Hg (THg) concentrations were up to 1.8-fold higher in lotic habitats than in lentic habitats and 37% higher in waterbodies with abundant wetlands along their margins than those without wetlands. Mercury concentrations in dragonflies differed among families but were correlated (r2 > 0.80) with each other, enabling adjustment to a consistent family to facilitate spatial comparisons among sampling units. Dragonfly THg concentrations were positively correlated with THg concentrations in both fish and amphibians from the same locations, indicating that dragonfly larvae are effective indicators of Hg bioavailability in aquatic food webs. We used these relationships to develop an integrated impairment index of Hg risk to aquatic ecosytems and found that 12% of site-years exceeded high or severe benchmarks of fish, wildlife, or human health risk. Collectively, this continental-scale study demonstrates the utility of dragonfly larvae for estimating the potential mercury risk to fish and wildlife in aquatic ecosystems and provides a framework for engaging citizen science as a component of landscape Hg monitoring programs.
Collapse
Affiliation(s)
- Collin A. Eagles-Smith
- United
States Geological Survey, Forest and Rangeland
Ecosystem Science Center, Corvallis, Oregon 97330, United States
| | - James J. Willacker
- United
States Geological Survey, Forest and Rangeland
Ecosystem Science Center, Corvallis, Oregon 97330, United States
| | - Sarah J. Nelson
- School
of Forest Resources, University of Maine, Orono, Maine 04469, United States
- Appalachian
Mountain Club, Gorham, New Hampshire 03581, United States
| | - Colleen M. Flanagan Pritz
- National
Park Service, Air Resources Division,
National Resource, Stewardship and Science Directorate, Lakewood, Colorado 80228, United States
| | - David P. Krabbenhoft
- United
States Geological Survey, Upper Midwest Water
Science Center, Middleton, Wisconsin 53562, United States
| | - Celia Y. Chen
- Department
of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755, United States
| | - Joshua T. Ackerman
- United
States Geological Survey, Western Ecological
Research Center, Dixon, California 95620, United States
| | - Evan H. Campbell Grant
- United
States Geological Survey, Patuxent Wildlife
Research Center, Turners Falls, Massachussetts 01376, United States
| | - David S. Pilliod
- United
States Geological Survey, Forest and Rangeland
Ecosystem Science Center, Boise, Idaho 83706, United States
| |
Collapse
|
15
|
Willacker JJ, Eagles-Smith CA, Blazer VS. Mercury bioaccumulation in freshwater fishes of the Chesapeake Bay watershed. ECOTOXICOLOGY (LONDON, ENGLAND) 2020; 29:459-484. [PMID: 32239332 DOI: 10.1007/s10646-020-02193-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 03/10/2020] [Indexed: 06/11/2023]
Abstract
Chemical contaminants are a threat to the Chesapeake Bay watershed, with mercury (Hg) among the most prevalent causes of impairment. Despite this, large-scale patterns of Hg concentrations, and the potential risks to fish, wildlife, and humans across the watershed, are poorly understood. We compiled fish Hg data from state monitoring programs and recent research efforts to address this knowledge gap and provide a comprehensive assessment of fish Hg concentrations in the watershed's freshwater habitats. The resulting dataset consisted of nearly 8000 total Hg (THg) concentrations from 600 locations. Across the watershed, fish THg concentrations spanned a 44-fold range, with mean concentrations varying by 2.6- and 8.8-fold among major sub-watersheds and individual 8-digit hydrological units, respectively. Although, mean THg concentrations tended to be moderate, fish frequently exceeded benchmarks for potential adverse health effects, with 45, 48, and 36% of all samples exceeding benchmarks for human, avian piscivore, and fish risk, respectively. Importantly, the percentage of fish exceeding these benchmarks was not uniform among species or locations. The variation in fish THg concentrations among species and sites highlights the roles of waterbody, landscape, and ecological processes in shaping broad patterns in Hg risk across the watershed. We outline an integrated Hg monitoring program that could identify key factors influencing Hg concentrations across the watershed and facilitate the implementation of management strategies to mitigate the risks posed by Hg.
Collapse
Affiliation(s)
- James J Willacker
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, 3200 SW Jefferson Way, Corvallis, OR, 97331, USA
| | - Collin A Eagles-Smith
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, 3200 SW Jefferson Way, Corvallis, OR, 97331, USA.
| | - Vicki S Blazer
- U.S. Geological Survey, Leetown Science Center, National Fish Health Research Laboratory, 11649 Leetown Road, Kearneysville, WV, 25430, USA
| |
Collapse
|
16
|
Willacker JJ, Eagles-Smith CA, Kowalski BM, Danehy RJ, Jackson AK, Adams EM, Evers DC, Eckley CS, Tate MT, Krabbenhoft DP. Timber harvest alters mercury bioaccumulation and food web structure in headwater streams. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 253:636-645. [PMID: 31330355 PMCID: PMC6799996 DOI: 10.1016/j.envpol.2019.07.025] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 07/02/2019] [Accepted: 07/05/2019] [Indexed: 05/15/2023]
Abstract
Timber harvest has many effects on aquatic ecosystems, including changes in hydrological, biogeochemical, and ecological processes that can influence mercury (Hg) cycling. Although timber harvest's influence on aqueous Hg transformation and transport are well studied, the effects on Hg bioaccumulation are not. We evaluated Hg bioaccumulation, biomagnification, and food web structure in 10 paired catchments that were either clear-cut in their entirety, clear-cut except for an 8-m wide riparian buffer, or left unharvested. Average mercury concentrations in aquatic biota from clear-cut catchments were 50% higher than in reference catchments and 165% higher than in catchments with a riparian buffer. Mercury concentrations in aquatic invertebrates and salamanders were not correlated with aqueous THg or MeHg concentrations, but rather treatment effects appeared to correspond with differences in the utilization of terrestrial and aquatic basal resources in the stream food webs. Carbon and nitrogen isotope data suggest that a diminished shredder niche in the clear-cut catchments contributed to lower basal resource diversity compared with the reference of buffered treatments, and that elevated Hg concentrations in the clear-cut catchments reflect an increased reliance on aquatic resources in clear-cut catchments. In contrast, catchments with riparian buffers had higher basal resource diversity than the reference catchments, indicative of more balanced utilization of terrestrial and aquatic resources. Further, following timber harvest THg concentrations in riparian songbirds were elevated, suggesting an influence of timber harvest on Hg export to riparian food webs. These data, coupled with comparisons of individual feeding guilds, indicate that changes in organic matter sources and associated effects on stream food web structure are important mechanisms by which timber harvest modifies Hg bioaccumulation in headwater streams and riparian consumers.
Collapse
Affiliation(s)
- James J Willacker
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, 3200 SW Jefferson Way, Corvallis, OR, 97331, USA
| | - Collin A Eagles-Smith
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, 3200 SW Jefferson Way, Corvallis, OR, 97331, USA.
| | - Brandon M Kowalski
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, 3200 SW Jefferson Way, Corvallis, OR, 97331, USA
| | - Robert J Danehy
- Catchment Aquatic Ecology, 5335 Saratoga St., Eugene, OR, 97405, USA
| | - Allyson K Jackson
- Oregon State University, Department of Fisheries and Wildlife, 104 Nash Hall, Corvallis, OR, 97331, USA
| | - Evan M Adams
- Biodiversity Research Institute, 276 Canco Road, Portland, ME, 04103, USA
| | - David C Evers
- Biodiversity Research Institute, 276 Canco Road, Portland, ME, 04103, USA
| | - Chris S Eckley
- U.S. Environmental Protection Agency, Region-10, 1200 6th Ave, Seattle, WA, 98101, USA
| | - Michael T Tate
- U.S. Geological Survey, Wisconsin Water Science Center, 8505 Research Way, Middleton, WI, 53562, USA
| | - David P Krabbenhoft
- U.S. Geological Survey, Wisconsin Water Science Center, 8505 Research Way, Middleton, WI, 53562, USA
| |
Collapse
|
17
|
Broadley HJ, Cottingham KL, Baer NA, Weathers KC, Ewing HA, Chaves-Ulloa R, Chickering J, Wilson AM, Shrestha J, Chen CY. Factors affecting MeHg bioaccumulation in stream biota: the role of dissolved organic carbon and diet. ECOTOXICOLOGY (LONDON, ENGLAND) 2019; 28:949-963. [PMID: 31410744 PMCID: PMC6814552 DOI: 10.1007/s10646-019-02086-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 07/22/2019] [Indexed: 05/15/2023]
Abstract
The bioaccumulation of the neurotoxin methylmercury (MeHg) in freshwater ecosystems is thought to be mediated by both water chemistry (e.g., dissolved organic carbon [DOC] and dissolved mercury [Hg]) and diet (e.g., trophic position and diet composition). Hg in small streams is of particular interest given their role as a link between terrestrial and aquatic processes. Terrestrial processes determine the quantity and quality of streamwater DOC, which in turn influence the quantity and bioavailability of dissolved MeHg. To better understand the effects of water chemistry and diet on Hg bioaccumulation in stream biota, we measured DOC and dissolved Hg in stream water and mercury concentration in three benthic invertebrate taxa and three fish species across up to 12 tributary streams in a forested watershed in New Hampshire, USA. As expected, dissolved total mercury (THg) and MeHg concentrations increased linearly with DOC. However, mercury concentrations in fish and invertebrates varied non-linearly, with maximum bioaccumulation at intermediate DOC concentrations, which suggests that MeHg bioavailability may be reduced at high levels of DOC. Further, MeHg and THg concentrations in invertebrates and fish, respectively, increased with δ15N (suggesting trophic position) but were not associated with δ13C. These results show that even though MeHg in water is strongly determined by DOC concentrations, mercury bioaccumulation in stream food webs is the result of both MeHg availability in stream water and trophic position.
Collapse
Affiliation(s)
- Hannah J Broadley
- Department of Environmental Conservation, University of Massachusetts, Amherst, MA, 01003, USA.
- Department of Biological Sciences, Dartmouth College, Hanover, NH, 03755, USA.
- Environmental Studies Program, Bates College, Lewiston, ME, 04240, USA.
| | | | - Nicholas A Baer
- Department of Natural and Environmental Sciences, Colby-Sawyer College, New London, NH, 03257, USA
| | | | - Holly A Ewing
- Environmental Studies Program, Bates College, Lewiston, ME, 04240, USA
| | - Ramsa Chaves-Ulloa
- Department of Biological Sciences, Dartmouth College, Hanover, NH, 03755, USA
- Department of General Education, Western Governors University, Salt Lake City, UT, USA
| | - Jessica Chickering
- Department of Natural and Environmental Sciences, Colby-Sawyer College, New London, NH, 03257, USA
| | - Adam M Wilson
- Department of Natural and Environmental Sciences, Colby-Sawyer College, New London, NH, 03257, USA
| | - Jenisha Shrestha
- Department of Natural and Environmental Sciences, Colby-Sawyer College, New London, NH, 03257, USA
| | - Celia Y Chen
- Department of Biological Sciences, Dartmouth College, Hanover, NH, 03755, USA
| |
Collapse
|
18
|
Melwani AR, Negrey J, Heim WA, Coale KH, Stephenson MD, Davis JA. Factors influencing methylmercury contamination of black bass from California reservoirs. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 251:850-861. [PMID: 31125815 DOI: 10.1016/j.envpol.2019.05.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 04/30/2019] [Accepted: 05/05/2019] [Indexed: 06/09/2023]
Abstract
Understanding how mercury (Hg) accumulates in the aquatic food web requires information on the factors driving methylmercury (MeHg) contamination. This paper employs data on MeHg in muscle tissue of three black bass species (Largemouth Bass, Spotted Bass, and Smallmouth Bass) sampled from 21 reservoirs in California. During a two-year period, reservoirs were sampled for total Hg in sediment, total Hg and MeHg in water, chlorophyll a, organic carbon, sulfate, dissolved oxygen, pH, conductivity, and temperature. These data, combined with land-use statistics and reservoir morphometry, were used to investigate relationships to size-normalized black bass MeHg concentrations. Significant correlations to black bass MeHg were observed for total Hg in sediment, total Hg and MeHg in surface water, and forested area. A multivariate statistical model predicted Largemouth Bass MeHg as a function of total Hg in sediment, MeHg in surface water, specific conductivity, total Hg in soils, and forested area. Comparison to historical reservoir sediment data suggested there has been no significant decline in sediment total Hg at five northern California reservoirs during the past 20 years. Overall, total Hg in sediment was indicated as the most influential factor associated with black bass MeHg contamination. The results of this study improve understanding of how MeHg varies in California reservoirs and the factors that correlate with fish MeHg contamination.
Collapse
Affiliation(s)
- Aroon R Melwani
- San Francisco Estuary Institute, 4911 Central Ave, Richmond, CA, 94804, USA.
| | - John Negrey
- Moss Landing Marine Laboratories, 7544 Sandholdt Road, Moss Landing, CA, 95039, USA
| | - Wes A Heim
- Moss Landing Marine Laboratories, 7544 Sandholdt Road, Moss Landing, CA, 95039, USA
| | - Kenneth H Coale
- Moss Landing Marine Laboratories, 8272 Moss Landing Road, Moss Landing, CA, 95039, USA
| | - Mark D Stephenson
- Moss Landing Marine Laboratories, 7544 Sandholdt Road, Moss Landing, CA, 95039, USA
| | - Jay A Davis
- San Francisco Estuary Institute, 4911 Central Ave, Richmond, CA, 94804, USA
| |
Collapse
|
19
|
Yan H, Li Q, Yuan Z, Jin S, Jing M. Research Progress of Mercury Bioaccumulation in the Aquatic Food Chain, China: A Review. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2019; 102:612-620. [PMID: 31101929 DOI: 10.1007/s00128-019-02629-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2018] [Accepted: 05/06/2019] [Indexed: 06/09/2023]
Abstract
Research on mercury (Hg) in aquatic ecosystems in China has focused mainly on fish, with little research on the base of the food chain and Hg bioaccumulation mechanisms. This paper summarizes research progress pertaining to the characteristics, current status, and trends of Hg accumulation in the aquatic food chain in China, analyzes the effects of human activities on the transmission and accumulation of Hg in aquatic food chains, and assesses their risks to human and ecosystem health. A comparison of fish samples in China between 2000 and 2018 indicates that their total Hg content remains at relatively safe levels. However, because current information is generally insufficient to confirm how anthropogenic activities affect transformation and bioaccumulation in the aqueous environment, Hg isotope studies should be a focus of research on aquatic food webs. Additionally, more attention should be paid to Hg transport and bioaccumulation in the basic food chain by focusing on multi-contaminant joint exposure studies and establishing Hg bio-transport models.
Collapse
Affiliation(s)
- Haiyu Yan
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550081, China
| | - Qiuhua Li
- Key Laboratory for Information System of Mountainous Area and Protection of Ecological Environment of Guizhou Province, Guizhou Normal University, Guiyang, 550001, China.
| | - Zhenhui Yuan
- Key Laboratory for Information System of Mountainous Area and Protection of Ecological Environment of Guizhou Province, Guizhou Normal University, Guiyang, 550001, China
| | - Shuang Jin
- Key Laboratory for Information System of Mountainous Area and Protection of Ecological Environment of Guizhou Province, Guizhou Normal University, Guiyang, 550001, China
- International Joint Research Centre for Aquatic Ecology, Guizhou Normal University, Guiyang, 550001, China
| | - Min Jing
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550081, China
- University of Chinese Academy of Sciences, Beijing, 100049, People's Republic of China
| |
Collapse
|
20
|
Eagles-Smith CA, Silbergeld EK, Basu N, Bustamante P, Diaz-Barriga F, Hopkins WA, Kidd KA, Nyland JF. Modulators of mercury risk to wildlife and humans in the context of rapid global change. AMBIO 2018; 47:170-197. [PMID: 29388128 PMCID: PMC5794686 DOI: 10.1007/s13280-017-1011-x] [Citation(s) in RCA: 193] [Impact Index Per Article: 32.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Environmental mercury (Hg) contamination is an urgent global health threat. The complexity of Hg in the environment can hinder accurate determination of ecological and human health risks, particularly within the context of the rapid global changes that are altering many ecological processes, socioeconomic patterns, and other factors like infectious disease incidence, which can affect Hg exposures and health outcomes. However, the success of global Hg-reduction efforts depends on accurate assessments of their effectiveness in reducing health risks. In this paper, we examine the role that key extrinsic and intrinsic drivers play on several aspects of Hg risk to humans and organisms in the environment. We do so within three key domains of ecological and human health risk. First, we examine how extrinsic global change drivers influence pathways of Hg bioaccumulation and biomagnification through food webs. Next, we describe how extrinsic socioeconomic drivers at a global scale, and intrinsic individual-level drivers, influence human Hg exposure. Finally, we address how the adverse health effects of Hg in humans and wildlife are modulated by a range of extrinsic and intrinsic drivers within the context of rapid global change. Incorporating components of these three domains into research and monitoring will facilitate a more holistic understanding of how ecological and societal drivers interact to influence Hg health risks.
Collapse
Affiliation(s)
| | - Ellen K. Silbergeld
- Johns Hopkin Bloomberg School of Public Health, 615 N. Wolfe Street, E6644, Baltimore, MD 21205 USA
| | - Niladri Basu
- McGill University, 204-CINE Building, Montreal, QC H9X 3V9 Canada
| | - Paco Bustamante
- University of La Rochelle, laboratory of Littoral Environment and Societies, Littoral Environnement et Sociétés (LIENSs), LIENSs UMR 7266 CNRS-Université de La Rochelle, 2 rue Olympe de Gouges, 17000 La Rochelle, France
| | - Fernando Diaz-Barriga
- Center for Applied Research in Environment and Health at, Universidad Autonoma de San Luis Potosi, Avenida Venustiano Carranza No. 2405, Col Lomas los Filtros Código Postal, 78214 San Luis Potosí, SLP Mexico
| | - William A. Hopkins
- Department of Fish and Wildlife Conservation, 310 West Campus Drive Virginia Tech, Cheatham Hall, Room 106 (MC 0321), Blacksburg, VA 24061 USA
| | - Karen A. Kidd
- Department of Biology & School of Geography and Earth Sciences, McMaster University, 1280 Main Street W., Hamilton, ON L8S 4K1 Canada
| | - Jennifer F. Nyland
- Department of Biological Sciences, 1101 Camden Ave, Salisbury, MD 21801 USA
| |
Collapse
|
21
|
Klapstein SJ, O'Driscoll NJ. Methylmercury Biogeochemistry in Freshwater Ecosystems: A Review Focusing on DOM and Photodemethylation. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2018; 100:14-25. [PMID: 29248954 DOI: 10.1007/s00128-017-2236-x] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Accepted: 12/02/2017] [Indexed: 05/16/2023]
Abstract
Mercury contamination is a growing concern for freshwater food webs in ecosystems without point sources of mercury. Methylmercury (MeHg) is of particular concern, as this is the form of mercury that crosses the blood-brain barrier and is neurotoxic to organisms. Wetlands and benthic sediments have high organic content and low oxygen availability. Anaerobic bacteria drive the metabolic function in these ecosystems and subsequently can methylate mercury. The bioavailability of MeHg is controlled by physicochemical characteristics such as pH, binding affinities, and dissolved organic matter (DOM). Similarly, photodemethylation is influenced by similar characteristics and thereby the two processes should be studied in tandem. The degradation of MeHg through photochemistry is an effective destruction mechanism in freshwater lakes. This review will highlight the uncertainties and known effects of DOM on subsequent photoreactions that lead to the occurrence of mercury photodemethylation and reduction in mercury bioavailability in freshwater ecosystems.
Collapse
Affiliation(s)
- Sara J Klapstein
- Environmental Sciences Program, Memorial University of Newfoundland, St. John's, NL, Canada.
- Earth and Environmental Science Department, Acadia University, Wolfville, NS, Canada.
| | - Nelson J O'Driscoll
- Earth and Environmental Science Department, Acadia University, Wolfville, NS, Canada
| |
Collapse
|
22
|
Alpers CN, Yee JL, Ackerman JT, Orlando JL, Slotton DG, Marvin-DiPasquale MC. Prediction of fish and sediment mercury in streams using landscape variables and historical mining. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 571:364-379. [PMID: 27378154 DOI: 10.1016/j.scitotenv.2016.05.088] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/01/2016] [Revised: 05/11/2016] [Accepted: 05/13/2016] [Indexed: 06/06/2023]
Abstract
Widespread mercury (Hg) contamination of aquatic systems in the Sierra Nevada of California, U.S., is associated with historical use to enhance gold (Au) recovery by amalgamation. In areas affected by historical Au mining operations, including the western slope of the Sierra Nevada and downstream areas in northern California, such as San Francisco Bay and the Sacramento River-San Joaquin River Delta, microbial conversion of Hg to methylmercury (MeHg) leads to bioaccumulation of MeHg in food webs, and increased risks to humans and wildlife. This study focused on developing a predictive model for THg in stream fish tissue based on geospatial data, including land use/land cover data, and the distribution of legacy Au mines. Data on total mercury (THg) and MeHg concentrations in fish tissue and streambed sediment collected during 1980-2012 from stream sites in the Sierra Nevada, California were combined with geospatial data to estimate fish THg concentrations across the landscape. THg concentrations of five fish species (Brown Trout, Rainbow Trout, Sacramento Pikeminnow, Sacramento Sucker, and Smallmouth Bass) within stream sections were predicted using multi-model inference based on Akaike Information Criteria, using geospatial data for mining history and landscape characteristics as well as fish species and length (r(2)=0.61, p<0.001). Including THg concentrations in streambed sediment did not improve the model's fit, however including MeHg concentrations in streambed sediment, organic content (loss on ignition), and sediment grain size resulted in an improved fit (r(2)=0.63, p<0.001). These models can be used to estimate THg concentrations in stream fish based on landscape variables in the Sierra Nevada in areas where direct measurements of THg concentration in fish are unavailable.
Collapse
Affiliation(s)
- Charles N Alpers
- U.S. Geological Survey, California Water Science Center, 6000 J Street, Placer Hall, Sacramento, CA 95819, U.S.A..
| | - Julie L Yee
- U.S. Geological Survey, Western Ecological Research Center, Dixon Field Station, 800 Business Park Drive, Suite D, Dixon, CA 95620, U.S.A
| | - Joshua T Ackerman
- U.S. Geological Survey, Western Ecological Research Center, Dixon Field Station, 800 Business Park Drive, Suite D, Dixon, CA 95620, U.S.A
| | - James L Orlando
- U.S. Geological Survey, California Water Science Center, 6000 J Street, Placer Hall, Sacramento, CA 95819, U.S.A
| | - Darrel G Slotton
- Dept. of Environmental Science and Policy, Univ. of California, Davis, CA 95616, U.S.A
| | - Mark C Marvin-DiPasquale
- U.S. Geological Survey, National Research Program, 345 Middlefield Road, Menlo Park, CA 94025, U.S.A
| |
Collapse
|
23
|
Eagles-Smith CA, Ackerman JT, Willacker JJ, Tate MT, Lutz MA, Fleck JA, Stewart AR, Wiener JG, Evers DC, Lepak JM, Davis JA, Pritz CF. Spatial and temporal patterns of mercury concentrations in freshwater fish across the Western United States and Canada. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 568:1171-1184. [PMID: 27102274 DOI: 10.1016/j.scitotenv.2016.03.229] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Revised: 03/17/2016] [Accepted: 03/17/2016] [Indexed: 05/25/2023]
Abstract
Methylmercury contamination of fish is a global threat to environmental health. Mercury (Hg) monitoring programs are valuable for generating data that can be compiled for spatially broad syntheses to identify emergent ecosystem properties that influence fish Hg bioaccumulation. Fish total Hg (THg) concentrations were evaluated across the Western United States (US) and Canada, a region defined by extreme gradients in habitat structure and water management. A database was compiled with THg concentrations in 96,310 fish that comprised 206 species from 4262 locations, and used to evaluate the spatial distribution of fish THg across the region and effects of species, foraging guilds, habitats, and ecoregions. Areas of elevated THg exposure were identified by developing a relativized estimate of fish mercury concentrations at a watershed scale that accounted for the variability associated with fish species, fish size, and site effects. THg concentrations in fish muscle ranged between 0.001 and 28.4 (μg/g wet weight (ww)) with a geometric mean of 0.17. Overall, 30% of individual fish samples and 17% of means by location exceeded the 0.30μg/g ww US EPA fish tissue criterion. Fish THg concentrations differed among habitat types, with riverine habitats consistently higher than lacustrine habitats. Importantly, fish THg concentrations were not correlated with sediment THg concentrations at a watershed scale, but were weakly correlated with sediment MeHg concentrations, suggesting that factors influencing MeHg production may be more important than inorganic Hg loading for determining fish MeHg exposure. There was large heterogeneity in fish THg concentrations across the landscape; THg concentrations were generally higher in semi-arid and arid regions such as the Great Basin and Desert Southwest, than in temperate forests. Results suggest that fish mercury exposure is widespread throughout Western US and Canada, and that species, habitat type, and region play an important role in influencing ecological risk of mercury in aquatic ecosystems.
Collapse
Affiliation(s)
- Collin A Eagles-Smith
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, 3200 SW Jefferson Way, Corvallis, OR 97331, USA.
| | - Joshua T Ackerman
- U.S. Geological Survey, Western Ecological Research Center, Dixon Field Station, 800 Business Park Drive, Suite D, Dixon, CA 95620, USA
| | - James J Willacker
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, 3200 SW Jefferson Way, Corvallis, OR 97331, USA
| | - Michael T Tate
- U.S. Geological Survey, Wisconsin Water Science Center, 8505 Research Way, Middleton, WI 53562, USA
| | - Michelle A Lutz
- U.S. Geological Survey, Wisconsin Water Science Center, 8505 Research Way, Middleton, WI 53562, USA
| | - Jacob A Fleck
- U.S. Geological Survey, California Water Science Center, 6000 J St. Placer Hall, Sacramento, CA 95819, USA
| | - A Robin Stewart
- U.S. Geological Survey, 345 Middlefield Road, Menlo Park, CA 94025, USA
| | - James G Wiener
- University of Wisconsin La Crosse, River Studies Center, 1725 State Street, La Crosse, WI 54601, USA
| | - David C Evers
- Biodiversity Research Institute, 276 Canco Road, Portland, ME 04103, USA
| | - Jesse M Lepak
- Colorado Parks and Wildlife, 317 West Prospect Road, Fort Collins, CO 80526, USA
| | - Jay A Davis
- San Francisco Estuary Institute, 4911 Central Ave, Richmond, CA 94804, USA
| | | |
Collapse
|
24
|
Fleck JA, Marvin-DiPasquale M, Eagles-Smith CA, Ackerman JT, Lutz MA, Tate M, Alpers CN, Hall BD, Krabbenhoft DP, Eckley CS. Mercury and methylmercury in aquatic sediment across western North America. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 568:727-738. [PMID: 27130329 DOI: 10.1016/j.scitotenv.2016.03.044] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2015] [Revised: 03/07/2016] [Accepted: 03/07/2016] [Indexed: 05/25/2023]
Abstract
Large-scale assessments are valuable in identifying primary factors controlling total mercury (THg) and monomethyl mercury (MeHg) concentrations, and distribution in aquatic ecosystems. Bed sediment THg and MeHg concentrations were compiled for >16,000 samples collected from aquatic habitats throughout the West between 1965 and 2013. The influence of aquatic feature type (canals, estuaries, lakes, and streams), and environmental setting (agriculture, forest, open-water, range, wetland, and urban) on THg and MeHg concentrations was examined. THg concentrations were highest in lake (29.3±6.5μgkg(-1)) and canal (28.6±6.9μgkg(-1)) sites, and lowest in stream (20.7±4.6μgkg(-1)) and estuarine (23.6±5.6μgkg(-1)) sites, which was partially a result of differences in grain size related to hydrologic gradients. By environmental setting, open-water (36.8±2.2μgkg(-1)) and forested (32.0±2.7μgkg(-1)) sites generally had the highest THg concentrations, followed by wetland sites (28.9±1.7μgkg(-1)), rangeland (25.5±1.5μgkg(-1)), agriculture (23.4±2.0μgkg(-1)), and urban (22.7±2.1μgkg(-1)) sites. MeHg concentrations also were highest in lakes (0.55±0.05μgkg(-1)) and canals (0.54±0.11μgkg(-1)), but, in contrast to THg, MeHg concentrations were lowest in open-water sites (0.22±0.03μgkg(-1)). The median percent MeHg (relative to THg) for the western region was 0.7%, indicating an overall low methylation efficiency; however, a significant subset of data (n>100) had percentages that represent elevated methylation efficiency (>6%). MeHg concentrations were weakly correlated with THg (r(2)=0.25) across western North America. Overall, these results highlight the large spatial variability in sediment THg and MeHg concentrations throughout western North America and underscore the important roles that landscape and land-use characteristics have on the MeHg cycle.
Collapse
Affiliation(s)
- Jacob A Fleck
- United States Geological Survey, California Water Science Center, 6000 J St., Placer Hall, Sacramento, CA 95819, USA.
| | | | - Collin A Eagles-Smith
- United States Geological Survey, Forest and Rangeland Ecosystem Science Center, Corvallis, OR, USA
| | - Joshua T Ackerman
- United States Geological Survey, Western Ecological Research Center, Dixon Field Station, 800 Business Park Drive, Suite D, Dixon, CA 95620, USA
| | - Michelle A Lutz
- United States Geological Survey, 8505 Research Way, Middleton, WI 53562, USA
| | - Michael Tate
- United States Geological Survey, 8505 Research Way, Middleton, WI 53562, USA
| | - Charles N Alpers
- United States Geological Survey, California Water Science Center, 6000 J St., Placer Hall, Sacramento, CA 95819, USA
| | - Britt D Hall
- Department of Biology, University of Regina, 3737 Wascana Parkway, Regina, SK S4S 0A2, Canada
| | - David P Krabbenhoft
- United States Geological Survey, 8505 Research Way, Middleton, WI 53562, USA
| | - Chris S Eckley
- United States Environmental Protection Agency, 1200 6th Ave, St. 900, OEA-095, Seattle, WA 98101, USA
| |
Collapse
|
25
|
Eagles-Smith CA, Wiener JG, Eckley CS, Willacker JJ, Evers DC, Marvin-DiPasquale M, Obrist D, Fleck JA, Aiken GR, Lepak JM, Jackson AK, Webster JP, Stewart AR, Davis JA, Alpers CN, Ackerman JT. Mercury in western North America: A synthesis of environmental contamination, fluxes, bioaccumulation, and risk to fish and wildlife. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 568:1213-1226. [PMID: 27320732 DOI: 10.1016/j.scitotenv.2016.05.094] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Revised: 05/12/2016] [Accepted: 05/13/2016] [Indexed: 05/25/2023]
Abstract
Western North America is a region defined by extreme gradients in geomorphology and climate, which support a diverse array of ecological communities and natural resources. The region also has extreme gradients in mercury (Hg) contamination due to a broad distribution of inorganic Hg sources. These diverse Hg sources and a varied landscape create a unique and complex mosaic of ecological risk from Hg impairment associated with differential methylmercury (MeHg) production and bioaccumulation. Understanding the landscape-scale variation in the magnitude and relative importance of processes associated with Hg transport, methylation, and MeHg bioaccumulation requires a multidisciplinary synthesis that transcends small-scale variability. The Western North America Mercury Synthesis compiled, analyzed, and interpreted spatial and temporal patterns and drivers of Hg and MeHg in air, soil, vegetation, sediments, fish, and wildlife across western North America. This collaboration evaluated the potential risk from Hg to fish, and wildlife health, human exposure, and examined resource management activities that influenced the risk of Hg contamination. This paper integrates the key information presented across the individual papers that comprise the synthesis. The compiled information indicates that Hg contamination is widespread, but heterogeneous, across western North America. The storage and transport of inorganic Hg across landscape gradients are largely regulated by climate and land-cover factors such as plant productivity and precipitation. Importantly, there was a striking lack of concordance between pools and sources of inorganic Hg, and MeHg in aquatic food webs. Additionally, water management had a widespread influence on MeHg bioaccumulation in aquatic ecosystems, whereas mining impacts where relatively localized. These results highlight the decoupling of inorganic Hg sources with MeHg production and bioaccumulation. Together the findings indicate that developing efforts to control MeHg production in the West may be particularly beneficial for reducing food web exposure instead of efforts to simply control inorganic Hg sources.
Collapse
Affiliation(s)
- Collin A Eagles-Smith
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, 3200 SW Jefferson Way, Corvallis, OR 97331, USA.
| | - James G Wiener
- University of Wisconsin La Crosse, River Studies Center, 1725 State Street, La Crosse, WI 54601, USA
| | - Chris S Eckley
- U.S. Environmental Protection Agency, Region-10, 2100 6th Ave., Suite 900, Seattle, WA 98101, USA
| | - James J Willacker
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, 3200 SW Jefferson Way, Corvallis, OR 97331, USA
| | - David C Evers
- Biodiversity Research Institute, 276 Canco Road, Portland, ME 04103, USA
| | | | - Daniel Obrist
- Desert Research Institute, Division of Atmospheric Sciences, 2215 Raggio Parkway, Reno, NV 89512, USA
| | - Jacob A Fleck
- U.S. Geological Survey, California Water Science Center, 6000 J St., Placer Hall, Sacramento, CA 95819, USA
| | - George R Aiken
- U.S. Geological Survey, National Research Program, 3215 Marine St., Boulder, CO 80303, USA
| | - Jesse M Lepak
- Colorado Parks and Wildlife, 317 West Prospect Road, Fort Collins, CO 80526, USA
| | - Allyson K Jackson
- Oregon State University, Department of Fisheries and Wildlife, 104 Nash Hall, Corvallis, OR 97331, USA
| | - Jackson P Webster
- University of Colorado, Civil, Environmental, and Architectural Engineering, Boulder, CO 80309, USA
| | - A Robin Stewart
- U.S. Geological Survey, 345 Middlefield Road, Menlo Park, CA 94025, USA
| | - Jay A Davis
- San Francisco Estuary Institute, 4911 Central Ave., Richmond, CA 94804, USA
| | - Charles N Alpers
- U.S. Geological Survey, California Water Science Center, 6000 J St., Placer Hall, Sacramento, CA 95819, USA
| | - Joshua T Ackerman
- U.S. Geological Survey, Western Ecological Research Center, Dixon Field Station, 800 Business Park Drive, Dixon, CA 95620, USA
| |
Collapse
|
26
|
Stafford CP, Downs CC, Langner HW. Mercury Hazard Assessment for Piscivorous Wildlife in Glacier National Park. NORTHWEST SCIENCE 2016. [DOI: 10.3955/046.090.0406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|